Night vision devices are commonly used by military personnel for conducting operations in low light or night conditions. The night vision devices used by the military typically include image intensifier tubes and associated optics that convert infrared and near infrared light into viewable images. A common night vision device currently being used in the U.S. Army is the PVS7 night vision goggle, manufactured by ITT Corporation of Roanoke, Va.
Assemblies for mounting night vision devices to a helmet are well-known in the art. These mounting assemblies allow a user's hands to remain free while viewing a scene through the night vision device. It is also desirable for these mounting assemblies to be removable from the helmet so that they do not interfere with a user's actions when they are not needed, such as during the daytime or when a user parachutes from an airplane.
A night vision device may be attached to a helmet through a helmet attachment mechanism which acts as an interface between a helmet mount and the helmet. In previous designs, helmet attachment mechanisms have been attached to a helmet by a strap secured around the helmet, by fasteners or most recently, by a shroud plate as described in, for example, U.S. Pat. No. 6,751,810 to Prendergast, which is incorporated herein by reference.
Shroud plates have heretofore generally been attached to helmets by three screws which are threaded into three corresponding flanged threaded inserts drilled into the shell of the shroud plate. The screws are inserted from the inside of the helmet, through the helmet and into the flanged threaded inserts of the shroud plate. It has been found, however, that the holes for the screws are not drilled in exactly the same locations on each helmet. More specifically, it has been found that the placement of holes for the screws varies by about 0.1 inch per hole.
Additionally, some helmets, due to perhaps a previous night vision goggle mount attachment or to the attachment of internal support webbing for the user's head, already have a single hole drilled into the front center surface. Rather than risk compromise to the structural integrity of the helmet by drilling more holes and to minimize the time needed for retrofit, it is desirable to attach a shroud plate with one screw rather than three. Moreover, some helmets have no holes predrilled therein and it is desirable to minimize the number of holes needed for attachment to maintain structural integrity and minimize the time needed for attachment of a shroud plate.
Finally, it has been found that some helmets have a larger brim than others, and the larger brim makes the location of the release button on the shroud plate important to ease of use. Thus, it is desirable to have an attachment mechanism that allows a user to detach a night vision goggle mount despite having a brim on his or her helmet.
These and other issues exist with the helmet attachment mechanisms for night vision devices disclosed in the prior art. Consequently a need exists for a further improved helmet attachment mechanism.